Grover's quantum searching algorithm is optimal
Abstract
I show that for any number of oracle lookups up to about π/4 N, Grover's quantum searching algorithm gives the maximal possible probability of finding the desired element. I explain why this is also true for quantum algorithms which use measurements during the computation. I also show that unfortunately quantum searching cannot be parallelized better than by assigning different parts of the search space to independent quantum computers.
- Publication:
-
Physical Review A
- Pub Date:
- October 1999
- DOI:
- 10.1103/PhysRevA.60.2746
- arXiv:
- arXiv:quant-ph/9711070
- Bibcode:
- 1999PhRvA..60.2746Z
- Keywords:
-
- 03.67.Lx;
- 03.65.Bz;
- Quantum computation;
- Quantum Physics
- E-Print:
- 13 pages, LaTeX, essentially published version